Part of a digital mixer



FIG. 1 is a perspective view of the front, top and right side of a part of a digital mixer showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is an enlarged view at 3-3 lines in FIG. 1; and,

FIG. 4 is an enlarged view at 4-4 lines in FIG. 2.

The broken lines shown are included for the purpose of illustrating the environment of the design only and form no part of the claimed design. 

CLAIM The ornamental design for a part of a digital mixer, as shown and described. 